Trimble Access Intersection Routine

What I've done in the past under similar circumstances is use my tape to pull out from the corner in 3 directions with good geometry and set spikes and carefully note the distances in the notes and take my GNSS observation. Using two of the shots, under the cogo menu in Access, compute a point, do a distance-distance intersection to establish a coordinate on the corner. Then inverse that computed coordinate to the 3rd GNSS shot as a check.?ÿ

Menu - COGO - Compute Point is what you're looking for.

Any of those routines will allow you to use an observed point, or observe a point on the fly, for the basis of computations. GNSS or TS, doesn't matter.

Depending on how things lie upon the ground, my go-to routines are Bearing & Distance and Dist-Dist Intersect. I guess one could do 4-point or one of the other ones if they got creative enough.

For better accuracy I might even do two B&D comps and average them, checking the deltas/standard deviations before storing.

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(Edit to add: After you tap Calc, on the next screen change the "Store As" dropdown to "Az HD VD" to tie the point to the comp points. Then if you go to adjust/postprocess in TBC, and something shifts, that computed point will move with the points it was derived from.)

@rover83?ÿ

Unfortunately, I don't have TBC.?ÿ 🙁

good thread & responses

Are you trying to measure it??ÿ There's a routine in measure points where you can set up a A,B,C baseline.?ÿ C being your point of interest.?ÿ Take shots on A and B.?ÿ It calcs C and stores it.?ÿ This has saved my life many times.

Those routines are in Access under Cogo/compute point

I've found the intersection routine to be one of the most intuitive things in access and I don't typically find most of access to be intuitive at all.?ÿ

You have a few options give. That will all work. Even if you donƒ??t have TBC I would do as Rover stated just encase down the road you adjust something. Instead of storing as a grid. You will still get the grid value.?ÿ

now if you want to measure from a couple different points you can do that also. Angles only angles and distance or anything in between. Just use the same point number for your observations. Then go into cogo and compute average. ?ÿIt will work with any observation method topo point or observed or measure rounds etc.?ÿ

depending on the situation I still carry one of those gravity finders or dog deterrent or plumb bobs. If it can be seen withen a few feet your corner and you canƒ??t get points geometrically around it without having to move. I use the plumb bob and a couple nails and make a straight line in with string and then locate the nails along the line and measure my distances with my pocket tape. All so i have the dist from each nail to the corner and distance between the nails. I locate the nails and inverse ck vs measured tape distance etc. ?ÿthen cogo it in or do it back at the office. You can even set it up for vertical calc and check. If need be. There are a few offset routines that can accomplish some of the same things. With gps I often like the sun routine. If i can get a shadow cast.?ÿ

Personally I would...

Measure and store the vector to your point from two setups.

You probably want to set the measurement type to 'angles only' so you don't get the issue of the instrument trying to measure to your point with no prism. Or you could measure in DR mode.

Now use the two setup points and the measured azimuths to calculate the intersection point.?ÿ

If you have measured using DR you can compare the calculated distances to those measured as a 'peace of mind' check. DR measurements can be confused by clutter - so your point depends only on the azimuths, the distance is just a check.

And dont forget to to change the measurement type back to 'Angles and distance'

Thanks to all who offered solutions.?ÿ I appreciate all the advice and help!?ÿ ?ÿ

Posted by: @ncsudirtman

good thread & responses

too bad, TBC is great at computations of multiple types of observations in the network adjustment. It would have no trouble with a resection during a traverse

@robertusa I can attest to that. ?ÿResection, rtk vrs, rtk base and rover, traverses with two different robots . ?ÿOne of these days I will get some formal training on TBC. I am about the only one in our office that uses it for more than just downloads and converting as staked points to put in civil3d for qa/qc.?ÿ

Posted by: @olemanriver

One of these days I will get some formal training on TBC. I am about the only one in our office that uses it for more than just downloads and converting as staked points to put in civil3d for qa/qc.?ÿ

Why do they bother with TBC at all - you can do all that straight from Access

@jimcox Thatƒ??s the million dollar question. ?ÿIts the (insert company here) way. Thats are standards. Its the way surveyors do it here. ?ÿLol. I am a simple person so I will spend time trying different things and testing them to figure out the most assured way to check data quality and simplest way. ?ÿI remember when survey controller came up with the ck BS routine. Ot ch topo. ?ÿI mean i was training a company on the gps post processing and the manager i was training had to pause to ck some raw data from field crew. ?ÿOh the way they were cking to see about BS and such. So he got a bonus class from me. And we tested it for him. He said do you know how much time that will save me over cking 8 crews data.?ÿ

Posted by: @jimcox

Posted by: @olemanriver

One of these days I will get some formal training on TBC. I am about the only one in our office that uses it for more than just downloads and converting as staked points to put in civil3d for qa/qc.?ÿ

Why do they bother with TBC at all - you can do all that straight from Access

Care to give a class or two on your vast Access knowledge??ÿ ?ÿ(Wouldn't it be great if Surveyorconnect.com had a venue to do free "surveyor to surveyor" training?)

@firestix Oh I don't have that much knowledge on access. I am sure from what I have read on here there are many with greater knowledge than I. I was very comfortable training on Trimble Survey Controller before it's end of life. I have just used that knowledge since being back practicing on the private sector side to get me through with access.

I know time is limited but I have used the help menu to try and figure out new things and the Trimble Knowledge Center and youtube videos. In the last year I have just started using it myself. I bring home the equipment sometimes when the boss says can we do this. It is usually something he heard or saw. So I will create a scenario here on the farm from hand calcs to test and such.

When I catch the other crew chief in a good mood and I am out with him we will try some new things. It is funny around the first of the year we were doing a survey on a lot and needed to tie one more block corner for the boss. We were going to have to traverse a lot more than the budget allowed for one block corner because of trees and other obstructions etc. I walked down and hit it with RTK and re located the other 2 block corners we had already shot with gps and conventional. But the boss and other crew chief are fine with setting control and such with rtk but can't get them to locate a property corner. So my next step was I grabbed the 25 ft tape and went down and chained in some offset points I could see from instrument. Well I did 3 points and used cogo to compute all different distances and geometry. I missed the gps point about a tenth after squaring the north and east deltas. So he wanted more so I added 2 more offset points but made a blunder on the last cogo and through it the wrong way so missed by 15 ft. I said hold on I will figure it out. He said lets traverse. When I got back to the office I checked why all of a sudden I was off on the one point 15 ft. I had just reversed the from and to number is all. I recalked it and now with 5 offset points I hit by .05 ft to my gps and .03 ft to his position from traversing down etc.. That is one thing that has been hard to get use to is using old school methods with the new technology and not getting talked to as if I was nuts.

So many good cogo functions and multiple ways to use them in access when you are in one of those situations. I try and once a week just read the help menu on cogo for stuff like that just to keep it in my head. I despise having to set a fly nail to position something in the woods for one shot. When all i have to do is offset it someway If I can mathematically prove is correct like a few offset points and measure with tape or a couple points online and measure. it is usually those corners or something where you have one big tree on line type of things. We use to do it all the time when I was recording the angles and distances in a fied book. The data collector makes it even easier. Just have to figure out your inputs and such..?ÿ

When you are having a cold beer at the house relaxing set up the robot and set you some nails in a small circle randomly and then use the knowns as a way to check using multiple methods to one of the points in the middle. I always try and remember when doing these things strength of figure always helps. Also many times we are not building a watch.

I did a stone position not to long ago. On a metes and bounds survey. It was thick and nasty. I had fences and trees on line. I just pulled some distances set nails where I could. But I was drilled some on it. 3 points turned rounds to each then measured between each and to monument. we are talking a 5 foot diameter area just to get some stone that was over a half a foot in size.

I still have my old DMA forms for intersection I believe. If you are ever in a pickle feel free to call I will try and help. Oh if you use gps play around with the sun routine for offset.?ÿ I have stacked a range pole and used its shadow for that. Tested it many times and the secret is be on a defined edge of the shadow right when you store the point. So you kind of have to anticipate the shadow movement as sun moves very fast. I think you can use a compass and input the magnetic declination so it gets corrected. Or just adjust the better compasses to that. PM me if you need my number. But there are some power users on here way better than I am. I read what they say and then go and try and figure it out. I been so focused on the FS exam I have stopped for a while doing my testing stuff. But now that I have that behind me I will experiment more. I am slowly gathering PS and state specific info ow to prepare for next exams..

I always want multiple tools in my quiver and have confidence in what works in each situation. 90% of the time it is business as usual. But when a 18 wheeler parks over your control point and you really need to get a job done you improvise. Love having that bubble on top of the multitrack prism because now I can low crawl under the trailer and take a bs with my made mini rod from some althread. LOL...?ÿ The other crew chief had made up when we were locating some Man Holes and a whole fleet of tractor trailers were parked over them.

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Oh edited because I had a thought. Trimble makes an emulator that you can run on your computer for acces or atleast they made one for survey controller , So you could play around with it there. I don.t have any experience with the new ones but I would use Trimble Survey Controller one years ago and make a basic survey style of a manual instrument So I would have to hand enter hz and vt angle and slope distance. I used it to test busted traverses where someone would go back out and just turn an angle and call me with the new info to see if that was where it had gone awry.. But in the comfort of your home you could play around with the cogo stuff I reckon. maybe someone who knows how to obtain it from a dealer will hook you up.?ÿ

Posted by: @olemanriver

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Oh edited because I had a thought. Trimble makes an emulator that you can run on your computer for acces or atleast they made one for survey controller ,

They still do.

Works exactly like access on your controller (and you can choose which controller)

You can even use it in the field. Put it on a laptop with bluetooth and you can use it with GPS - and there is a cute device called Electronic Data Bridge (EDB) which will take bluetooth and convert to radio to connect to the S series instruments.

@firestix For training, there is a Youtube channel just for Trimble Access, with a whole heap of resources on it. Nothing too long or too hard. Take a look?ÿ - you might like to start here

@jimcox wow. do you have to be a certified instructor to get it or is it available to all who purchase. I know when I was a trainer I used the emulators all the time. It has been a long time but i think it only allowed so many points and or job size. It was not meant to be a production tool just made it nice to walk someone through step by step if need be.?ÿ

@olemanriver It is available to everyone. Not sure about the exact licensing details, I find Trimble a bit confusing, and it may differ geographically. Best to ask your distributor.